@ E.Y. O.K., no need to damn something or someone -- I think I'm almost there. I still have a blockade at this point: The splitting world describes the world from a all-knowing top-down perspective from where everything looks linear, unitary etc. But from our encapsulated one-world perspective we see this as a series of nonlinear accidents: particles hit at one point, only one point, given by the probabilities governed by the wave function. Entanglement breaks when we measure it. So what I meant was, the splitting produces the illusion for us that the world is non-linear. Wouldn't you say that from our perspective we would never be able to discriminate between both positions, if the non-linearity is true or if it's just an illusion of an superordinate process? I cannot see how you could get experimental verification from within this one world. Or as long as we just want to describe our one world, how we could get better results than by calling the non-linearity 'collapse' and go on with our maths.

If I missed something along the line, I'm really willing to learn.

To me, science is bound to explain human experiences by explaining qualities of the objects that form the world (I hope it's not too far fetched, I just made it up). Some qualities can be observed, even if it takes an LHC, some can't, at least we don't have any idea yet how. If then the world splitting can't be observed at all and all we know is our single resulting world then I guess science's task is to explain this single world. At least, from inside the single world that may look like the main task of science. I may be wrong, that's my thoughts right now.

In entangled systems, those systems only keep being entangled because they're experimentally protected from outside influences. I always understood collapse as a result of special interactions of the wave with the surrounding, particularly interactions which expose particle-like features of the wave-particle. It has nothing to do with distance or size. And I think that can be shown really nice in the double-slit experiment. So right there, there's no possibility in collapse theory that our brain or consciousness could be the referee of wave collapses. Before it gets to the brain, the wave function obviously has to interact. That's also an argument against the Earth's being a wave function. Wave and collapsed wave, in my understanding, explicitly behave differently, so we can't say it was a wave all along, we just never knew it.

Finally, if you substitute collapse for world splitting, wouldn't then world splitting produce the same effects and fulfill your last list quite as well as the collapse interpretation?

Nice series, really like it!

I have two arguments for going for Box B. First, for a scientist it's not unusual that every rational argument (=theory) predicts that only two-boxing makes sense. Still, if the experiment again and again refutes that, it's obviously the theory that's wrong and there's obviously something more to reality than that which fueled the theories. Actually, we even see dilemmas like Newcomb's in the contextuality of quantum measurements. Measurement tops rationality or theory, every time. That's why science is successful and philosophy is not.

Second, there's no question I choose box B. Either I get the million $ -- or I have proven an extragalactical superintelligence wrong. How cool is that? 1000$? Have you looked at the exchange rates lately?

Also, of course, the small guy in the mass is pretty much exchangable. The celebrity in front is not (or to a much smaller degree). Both know that.

Being a celebrity may protect one from consequences, that's true. On the other hand, that celeb people are held in higher regard has partly to do with their taking a 'bigger' risk: Most celebrities could live well without further engaging themselves. They also don't profit as much for themselves - the regular guy's life next to him could change drastically upon any progress reached, while the celebrity himself could still live well without any progress whatsoever (and lose more by the backlash).

Maybe I'm thinking more of Kasparov than Ghandi, but well...

Evolution resolves the infinite regression, not by being super-clever and super-efficient, but by being stupid and inefficient and working anyway. This is the marvel.

Stupid and inefficient is sometimes much better (and faster) than a meticulously designed process. If you've ever dealt with fitting of really complex data, a random walk is often suprinsingly more efficient than any of the refined fitting algorithms. In itself it's just stupid "trial and error" in endless repetition, just like evolution, with a little bit of organizing in the background.

I wonder if anyone ever remarked on the seemingly excellent evidence thus provided for Hinduism over Christianity. Probably not.

Well, David Hume did. In the Dialogues Concerning Natural Religion. Although not with a totally straight face.

The best book-long treatise about your points is probably Dawkins' The Selfish Gene. But you probably know that.